I got 7 Mandarin duck eggs in the mail, and on day 4 at least 3 of them are developing! I read that they do better under a broody hen, so I put 5 of the best looking ones under one...she's a bantam Cochin and couldn't hold any more lol The two in my incubator don't look to be developing, but it is still early. I'm very excited to add Mandarins to my place and hope they make it to hatch!